Human Genetics

, Volume 132, Issue 4, pp 473–480

Germline mutations of regulator of telomere elongation helicase 1, RTEL1, in Dyskeratosis congenita

  • Bari J. Ballew
  • Meredith Yeager
  • Kevin Jacobs
  • Neelam Giri
  • Joseph Boland
  • Laurie Burdett
  • Blanche P. Alter
  • Sharon A. Savage
Original Investigation

DOI: 10.1007/s00439-013-1265-8

Cite this article as:
Ballew, B.J., Yeager, M., Jacobs, K. et al. Hum Genet (2013) 132: 473. doi:10.1007/s00439-013-1265-8

Abstract

Dyskeratosis congenita (DC) is an inherited bone marrow failure and cancer predisposition syndrome caused by aberrant telomere biology. The classic triad of dysplastic nails, abnormal skin pigmentation, and oral leukoplakia is diagnostic of DC, but substantial clinical heterogeneity exists; the clinically severe variant Hoyeraal Hreidarsson syndrome (HH) also includes cerebellar hypoplasia, severe immunodeficiency, enteropathy, and intrauterine growth retardation. Germline mutations in telomere biology genes account for approximately one-half of known DC families. Using exome sequencing, we identified mutations in RTEL1, a helicase with critical telomeric functions, in two families with HH. In the first family, two siblings with HH and very short telomeres inherited a premature stop codon from their mother who has short telomeres. The proband from the second family has HH and inherited a premature stop codon in RTEL1 from his father and a missense mutation from his mother, who also has short telomeres. In addition, inheritance of only the missense mutation led to very short telomeres in the proband’s brother. Targeted sequencing identified a different RTEL1 missense mutation in one additional DC proband who has bone marrow failure and short telomeres. Both missense mutations affect the helicase domain of RTEL1, and three in silico prediction algorithms suggest that they are likely deleterious. The nonsense mutations both cause truncation of the RTEL1 protein, resulting in loss of the PIP box; this may abrogate an important protein–protein interaction. These findings implicate a new telomere biology gene, RTEL1, in the etiology of DC.

Supplementary material

439_2013_1265_MOESM1_ESM.pdf (14 kb)
Supplementary material 1 (PDF 13 kb)Online Resource 1: Exome coverage statistics. Exome coverage, off-target and on-target bases are indicated for two DC families
439_2013_1265_MOESM2_ESM.pdf (15 kb)
Supplementary material 2 (PDF 15 kb)Online Resource 2: Exome variant filtering strategy. Variants were sequentially filtered by the criteria described
439_2013_1265_MOESM3_ESM.pdf (29 kb)
Supplementary material 3 (PDF 29 kb)Online Resource 3: Variants found in RTEL1 by targeted sequencing. Targeted sequencing of RTEL1 exons revealed variants that were common (MAF > 1 %), synonymous, or predicted to be benign
439_2013_1265_MOESM4_ESM.pdf (15 kb)
Supplementary material 4 (PDF 15 kb)Online Resource 4: Primers for the RTEL1 locus used in IonTorrent sequencing. These primers were used for targeted sequencing of the RTEL1 exons

Copyright information

© Springer-Verlag Berlin Heidelberg (outside the USA) 2013

Authors and Affiliations

  • Bari J. Ballew
    • 1
  • Meredith Yeager
    • 2
  • Kevin Jacobs
    • 2
  • Neelam Giri
    • 1
  • Joseph Boland
    • 2
  • Laurie Burdett
    • 2
  • Blanche P. Alter
    • 1
  • Sharon A. Savage
    • 1
  1. 1.Clinical Genetics Branch, Division of Cancer Epidemiology and GeneticsNational Cancer InstituteRockvilleUSA
  2. 2.Cancer Genomics Research LaboratoryFrederickUSA